Overtime pay calculator 2026/27
Turn overtime hours and a pay multiplier into annual gross overtime and an estimated after-tax increase.
The gross overtime formula
Gross overtime equals base hourly rate × overtime multiplier × overtime hours per week × overtime weeks per year. A multiplier of 1.5 represents time-and-a-half; 2 represents double time.
How the net estimate is produced
Income Tax is the annual difference between base salary and base salary plus total overtime. NI and selected student loans use a weekly earnings-period model: the extra weekly deductions are multiplied by the number of overtime weeks entered.
Timing can change the payslip. If you are paid monthly, overtime is grouped differently from this weekly model. PAYE also uses tax-code and cumulative information. The result is an annual planning estimate, not a reproduction of a specific payroll run.
Before relying on recurring overtime
- Check whether the hours are guaranteed or optional.
- Confirm which hours qualify for the enhanced multiplier.
- Allow for unpaid breaks, holidays and weeks when overtime is unavailable.
- Do not build essential spending around overtime that can be withdrawn.
- Use the hourly-to-salary converter if you first need a base annual figure.